I think I have the depth information in the house inspection report somewhere. It certainly isn't written down anywhere in that pump house. The elevation change to the house is a goodly 75', but I am not that great at estimating elevation change. I don't have any great points of reference to use. I may take a laser level out to the drive with a 10' pole and get a more accurate reading that way. If it is 100 feet, then the grade would be 16%, and that seems high. 75 feet gives a grade of 11% and that is closer to likely.
I'll look for the actual depth - better yet I'll get the wife to do it because it means getting into the files and I never put things back right and I mess up her organization :/
If I just had a tilt meter for the tractor, I'd be able to tell you straight away what the grade was... sounds like a good excuse to me!
That constant pressure pump sounds awesome. I do expect to need to irrigate as well, but I am doing all drip, so I don't expect to need insane volumes. Maybe a 1-1.5HP would be all I need.